UNRAVELING ANCIENT MYSTERIES

A new breed of scientist, combining expertise in pathology and archeology, is examining the dried remains of ancient peoples to unravel their patterns of disease and death.

The paleopathologists, as they are called, tackle the mysteries of ancient deaths much as a modern coroner might try to determine the cause of a fatality today.

The main subjects of such studies-naturally desiccated mummies preserved with their organs intact-are far more revealing of ancient lifestyles than the eviscerated and embalmed mummies of ancient Egypt or the artifacts and food remains found at ancient dwelling sites.

The research holds promise for understanding both ancient cultures and diseases of the present.

An energetic example of the new breed of scientist is 65-year-old Arthur Aufderheide, a pathologist and amateur archeologist who recently retired as chairman of the pathology department at the University of Minnesota-Duluth.

He and his colleagues already have participated in some surprising discoveries. For example, they found a high incidence of osteoporosis among young women who died thousands of years ago in a desert in Chile.

They also have detected severe emphysema in a Chilean man in his mid-20s who died 1,500 years ago, advanced atherosclerosis in an 18th Century Aleutian woman who died in her early 50s and a lead-poisoning epidemic that devastated slaves who processed sugar cane in Barbados in the 17th Century.

But perhaps his most important contribution to paleopathology will be the application of analytic techniques to reconstruct the diets of ancient people with far greater detail and precision than ever before possible.

As a pathologist, Aufderheide is looking for correlations between dietary habits and patterns of disease, some of which may shed light on modern diet-related problems.

Why, for instance, do the spines of many Eskimo women who died 8,000 years ago-nearly all before age 40-look like the hunched backs of 85-year-old American women today?

Was the ancient diet deficient in calcium? Did certain commonly eaten plants block calcium absorption? Did excessive physical demands cause hormonal derangements that resulted in premature bone loss? Did they nurse their babies for so long that their own bodies became depleted of bone-building calcium?

''We are examining all these possibilities,'' Aufderheide said in an interview at his office in Duluth.

The studies of ancient Eskimos provide a clue to the prolonged nursing theory, he said.

Unlike other foods, milk contains no strontium. By analyzing for strontium in the bones of children who died, researchers can tell at what age they stopped nursing. The less strontium in the bones, the longer that child was nursing and perhaps the greater the calcium depletion in the mother.

In related research, Aufderheide found a very high incidence of childhood mortality in one group, with about 60 percent of the young children dying.

''We found high strontium levels in the bones of children by the age of 2, suggesting that mothers took them off the breast much earlier than usual,'' he said. ''This population may have been new to the area and, in their struggle to adapt, the women were forced to stop nursing prematurely.''

Aufderheide was practicing clinical pathology-seeing patients, analyzing tissues and blood-when the new medical school in Duluth invited him on board full time in 1977.

''I was 54,'' he said, ''and for the first time in my life, I had time for research, but I thought it was too late to get a Ph.D. in a new field.''

An inner voice, he says, began pushing him toward paleopathology, which would incorporate his lifelong interest in anthropology.

Recognizing that his strength was the analysis of soft tissues, his task was to find preserved mummies.

He read ferociously, analyzed environments and contacted anthropologists. Within 5 years, he had created a computer registry of where naturally preserved mummies could be found.